Recording ink, ink cartridge, ink record, inkjet recording apparatus, and inkjet recording method

ABSTRACT

The object of the invention to provide a recording ink with excellent discharge stability and storage stability, which rapidly penetrates into a recording medium and forms a coating, and which will never generate smearing upon high-speed printing or double-sided printing, and which excels in marker resistance, and which enables high quality image recording with less bleeding, and the ink cartridge, the ink record, the inkjet recording apparatus, and the inkjet recording method using the recording ink. The recording ink containing at least water, a colorant, a resin fine-particle, a water-soluble organic solvent and a penetrant, in which the penetrant is a diol compound whose carbon number is 7 to 11 and the resin fine-particle is a silicone modified acrylic resin not containing a hydrolyzable silyl group.

This is a divisional application of U.S. application Ser. No.11/575,444, filed May 22, 2008, now U.S. Pat. No. 7,810,919 which is a371 of PCT/JP05/17542 filed on Sep. 16, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording ink and an ink cartridge,ink record, an inkjet recording apparatus, and an inkjet recordingmethod using the recording ink.

2. Description of the Related Art

Dyes have conventionally been used as a colorant of ink for inkjetrecording. However, dye ink has the deficiency that it has less waterresistant properties and less atmospheric corrosion resistance, so iteasily blots on plain paper. In order to overcome these defects, pigmentink where pigment is used as a colorant has been proposed. Even thoughthis pigment ink has excellent water resistant properties andatmospheric corrosion resistance and enables recording of images withless bleeding, there is the problem that it has less fixation.

Therefore, the improvement of the fixation by adding various resins hasbeen attempted. For example, a method to record images with lessbleeding by adding thermoplastic resin emulsion to pigment ink isproposed (refer to Patent Literature 1). However, in this proposal,because drying by heating is performed, there is the deficiency that theapparatus becomes complex and that there is more consumption ofelectricity.

Further, an ink composition where an acrylic silicone resinfine-particle containing an alkoxysilyl group is used (refer to PatentLiterature 2) and a coating agent composed of reactivity resin emulsionhaving a hydrolyzable silyl group and an amine imide group (refer toPatent Literature 3) are proposed. However, these proposals do not takethe improvement of fixation and storage properties into consideration,making them unsuitable for practical use.

Further, Patent Literature 4 proposes a method where the emulsioncopolymerization of a vinyl monomer having a specific reactive silylgroup, which exists in the form of a salt, another vinyl monomer havinga reactive silyl group other than that mentioned above, and other vinylmonomer copolymerizable with these monomers results in the production ofpolymer emulsion while the hydrolyzable silyl group exists stably.

However, in this proposal, there is the deficiency that the resinfine-particle where the hydrolyzable silyl group remains reacts with theink, and causes a decrease of the long-term storage properties of theink.

Further, Patent Literature 5 proposes a recording liquid where emulsionresin, which is formed by the radical polymerization of an ethyleneunsaturated monomer in the presence of a radical reactivity emulsion,and pigment is dispersed in a aqueous medium. However, with thisproposal, there is no disclosure or suggestion regarding whether or notan alkoxysilyl group remains in the emulsion resin, and even though aleft standing test for a dispersion of the emulsion resin, glycerin andwater was conducted, since composition containing the emulsion resin,glycerin and water has high surface tension, it has less permeability toa recording medium. In addition, ink containing a resin component tendsto have less permeability because the ink is easily accumulated on arecording medium after printing. If high-speed printing or high-speeddouble side printing is performed using ink with inferior permeability,there is the problem that a roller for the purpose of conveying arecording medium rubs the printed portion immediately after printing,and smearing occurs.

Further, Patent Literature 6 proposes a method where a polymeric monomeris emulsion-polymerized and an organosiloxane compound is absorbed intothe obtained polymer particles and condensation occurs. In thisproposal, the particles themselves form a film with excellent tolerance.However, in the ink containing the pigment, in order to fix the pigmentand to add excellent abrasion resistance and marker resistance, itbecomes necessary to add a large quantity of resin fine-particle.However, with ink containing a large quantity of resin, there is theproblem that the ink dries out in the vicinity of a nozzle, whichdischarges the ink when printing, with the easy occurrence of dropletbend or no discharge.

Therefore, recording ink with excellent discharge stability and storagestability, which rapidly penetrates into a recording medium and forms acoating, and which will never generate smearing upon high-speed printingor double-sided printing, and which excels in marker resistance, andwhich enables high quality image recording with less bleeding, has notbeen provided yet, so the actual situation is that the promptdevelopment of ink is desired.

Patent Literature 1 Japanese Patent Application Laid-Open (JP-A) No.9-176533

Patent Literature 2 Japanese Patent (JP-B) No. 3011087

Patent Literature 3 Japanese Patent Application Laid-Open (JP-A) No.5-25354

Patent Literature 4 Japanese Patent Application Laid-Open (JP-A) No.6-157861

Patent Literature 5 Japanese Patent Application Laid-Open (JP-A) No.2002-294105

Patent Literature 6 Japanese Patent Application Laid-Open (JP-A) No.7-278480

SUMMARY OF THE INVENTION

The objective of the present invention is to provide recording ink withexcellent discharge stability and storage stability, which rapidlypenetrates into a recording medium and forms a film, and which generatesno smear upon high-speed printing or double-sided printing, and whichexcels in marker resistance, and which enables high quality imagerecording with less bleeding; and to provide an ink cartridge, an inkrecord, an inkjet recording apparatus and an inkjet recording methodusing the recording ink.

As a result of diligently repeating examinations by the inventors of thepresent application for the purpose of resolving the above-mentionedproblems; in the recording ink containing at least water, a colorant,resin fine-particle and a penetrant, in order to improve abrasionresistance and marker resistance, it has been discovered that siliconemodified acrylic resin not containing any hydrolyzable silyl group isthe most suitable for a resin that can form a strong film afterpenetrating into a recording medium and setting the colorant.

Further, it has been discovered that even if containing a resincomponent, using a dial compound having carbon number of 7 to 11 resultsin realizing an ink where the permeability into the recording medium isexcellent, high picture density is maintained, and no image bleedingoccurs.

The recording ink of the present invention comprising at least water, acolorant, resin fine-particle, a water-soluble organic solvent and apenetrant; the penetrant is a diol compound having carbon number of 7 to11; and the resin fine-particle is a silicone modified acrylic resin notcontaining a hydrolyzable silyl group.

In this aspect, the recording ink of the present invention, in which thevolume average particle diameter is 10 nm to 300 nm; the silicon (Si)quantity originated from the silicone modified acrylic resin in therecording ink is 50 ppm to 400 ppm; the minimum film forming temperature(MFT) of the resin fine-particle is 20° C. or lower; the water-solubleorganic solvent is at least one selected from glycerin, ethylene glycol,diethylene glycol, triethylene glycol, propylene glycol, dipropyleneglycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol,1,4-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, tetraethyleneglycol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, polyethylene glycol,1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone,N-methyl-2-pyrrolidone and N-hydroxyethyl-2-pyrrolidone; the colorant isat least one of a pigment, a dye and a colored fine-particle; thepigment has at least one hydrophilic group on the surface, and is atleast one of water dispersible and water soluble in the absence of adispersant; 0.05 parts by mass to 1.2 parts by mass of the siliconemodified acrylic resin fine-particles not containing a hydrolyzablesilyl group is added relative to 1 part by mass of pigment; a nonionicsurfactant is comprised, and the nonionic surfactant is at least oneselected from an acetylene glycol surfactant, polyoxyethylene alkylether, polyoxyethylene alkylphenyl ether, polyoxyethylene alky ester andpolyoxyethylene sorbitan fatty acid ester; a fluorochemical surfactantis comprised, and the fluorochemical surfactant is at least one selectedfrom the following Structural Formulae (1), (2) and (3); an anionicsurfactant is comprised, and the anionic surfactant is comprised and theanionic surfactant is at least one selected from polyoxyethylene alkylether acetate and dialkyl sulfosuccinate salt; an aminopropane diolcompound is further comprised; the viscosity of the recording ink at 25°C. is 7 mPa·sec. to 20 mPa·sec.; the solid content of the recording inkis 6% by mass to 20% by mass; at least one selected from cyan ink,magenta ink, yellow ink and black ink.CF₃CF₂(CF₂CF₂)_(m)—CH₂CH₂O(CH₂CH₂O)_(n)H  Structural Formula (1)

In the Structural Formula (1), ‘m’ is an integer of 0 to 10, and ‘n’ isan integer of 1 to 40.

in the Structural Formula (2), ‘Rf’ is CF₃ or CF₂CF₃, ‘m’ is an integerof 6 to 25, ‘n’ is an integer of 1 to 4, and ‘p’ is an integer of 1 to4.

in the Structural Formula (3), ‘Rf’ is CF₃ or CF₂CF₃, and ‘q’ is aninteger of 1 to 6. The ink cartridge of the present invention comprisesa container containing the recording ink, and the recording ink is therecording ink of the present invention.

The inkjet recording apparatus of the present invention has at least anink drops discharging unit configured to discharge a recording ink dropsto form an image by applying an impulse to the recording ink, and therecording ink is the recording ink of the present invention.

In this aspect, the impulse is at least one selected from heat,pressure, vibration and light; the inkjet recording apparatus has areversing unit configured to reverse a recording surface of therecording medium so as to enable double-sided printing; the inkjetrecording apparatus has an endless conveying belt, and a conveying unitconfigured to convey a recording medium by electrifying the surface ofthe endless conveying belt; the inkjet recording apparatus comprising asubtank for supplying the ink onto a recording head, and the ink issupplied from the ink cartridge to the subtank via a supply tube arepreferable.

The inkjet recording method of the present invention comprises at leasta recording ink drop discharging step of discharging an ink drops toform an image by applying the impulse to the recording ink, and therecording ink is the recording ink of the present invention.

The ink record of the present invention has an image formed onto arecording medium by using the recording ink, and the recording ink isthe recording ink of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing an example of the ink cartridge ofthe present invention.

FIG. 2 is an exemplary schematic view also including a case (outerpackage) of the ink cartridge case shown in FIG. 1.

FIG. 3 is an exemplary perspective diagram in the situation where acover of an ink cartridge loading section in the inkjet recordingapparatus is opened.

FIG. 4 is an exemplary schematic block diagram explaining the entireconstruction of the inkjet recording apparatus.

FIG. 5 is an enlarged schematic view showing an example of the inkjethead of the present invention.

FIG. 6 is an enlarged element view showing an example of the inkjet headof the present invention.

FIG. 7 is an enlarged cross sectional view of a main section showing anexample of the inkjet head of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(Recording Ink)

The recording ink of the present invention contains at least water, acolorant, resin fine-particle, a water-soluble organic solvent and apenetrant. The penetrant is a diol compound the carbon number of whichis 7 to 11. The resin fine-particle is composed of silicone modifiedacrylic resin not containing a hydrolyzable silyl group; and asurfactant, an aminopropanediol compound and other component(s) arecomposed, where necessary.

As the resin fine-particle, use is made of a silicone modified acrylicresin not containing a hydrolyzable silyl group, which can be obtainedby polymerizing an acrylic monomer and a silane compound in the presenceof an emulsifier.

As the polymerization, for example, radical polymerization, emulsionpolymerization, dispersion polymerization, seed polymerization andsuspension polymerization are provided.

Examples of the acrylic monomer are not particularly limited and may beselected appropriately according to the purpose. Examples thereofinclude acrylic ester monomers such as methyl acrylate, ethyl acrylate,butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, acryloylmorpholine, and N,N′-dimethylaminoethylacrylate; methacrylic estermonomers such as methyl methacrylate, ethyl methacrylate, butylmethacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate,N,N′-dimethylaminoethyl methacrylate; amide acrylates such asN-methylolacrylamide and methoxymethylacrylamide; carboxylicacid-containing monomers such as maleic acid, fumaric acid, itaconicacid, acrylic acid, methacrylic acid, and the like.

The emulsifier is not particularly limited and may be appropriatelyselected according to the purpose. Examples of the emulsifier includealkylbenzenesulfonic acid. and their salt, dialkylsulfosuccinic esterand their salt, alkylnaphthalenesulfonic acid and their salt,alkylnaphthalenesulfonic acid salt formalin condensates, higher fattyacid salt, higher fatty acid ester sulfonic acid salt, ethylenediaminepolyoxypropylene-polyoxyethylene condensates, sorbitan fatty acid esterand their salt, aromatic and aliphatic phosphoric acid ester and theirsalt, dodecylbenzene sulfonate, dodecylsulfate, laurylsulfate,dialkylsulfosuccinate, polyoxyethylenealkylphenylethersulfate,polyoxyethynealkylpropenylphenylethersulfate,alkylphenyletherdisulfonate, polyoxyethylenealkylphosphate,polyoxyethylenealkyletheracetate, polyoxyethylenelanoline alcohol ether,polyoxyethylenelanoline fatty acid ester, laurylalcohol ethoxylate,lauryl ether sulfuric ester salt, lauryletherphosphoric acid ester,sorbitan fatty acid ester, fatty acid diethanolamide,naphthalenesulfonic acid formalin condensates, and the like. Examples ofthese salts include sodium, ammonium, and the like.

Reactive emulsifiers having an unsaturated double bond can be used asthe emulsifier. Examples of the reactive emulsifier include commerciallyavailable Adekalia soap SE, NE, PP (by Asahi Denka), LATEMUL S-180 (byKao), ELEMINOL JS-2, ELEMINOL RS-30 (by Sanyo Kasei), and Aquaron RN-20(by Daiichi Kogyo Seiyaku).

The silane compound is not particularly limited and may be appropriatelyselected according to the purpose. Examples of the silane compoundinclude tetramethoxysilane, methyltrimethoxysilane,dimethyldimethoxysilane, phenyltrimethoxysilane,diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane,dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane,hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane,decyltriethoxysilane, trifluoropropyltrimethoxysilane, and the like.

Monomers generally known as silane coupling agents may be used as thesilane compound, examples of which monomers include vinyltrichlorsilane,vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane,3-methacryloxypropylmethyldimethoxysilane,3-methacryloxypropyltrimethoxysilane,3-methacryloxypropylmethyldiethoxysilane,3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane,N-2(aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane,3-aminopropyltriethoxysilane,3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine,N-phenyl-3-aminopropyltrimethoxysilane,N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloricacid salt, 3-ureidopropyltriethoxysilane,3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane,3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide,3-isocyanate propyltriethoxysilane, and the like.

The hydrolyzable silyl group in the silicone modified acrylic resin notcontaining a hydrolyzabile silyl group refers to a silyl groupcontaining a hydrolyzabile group. Examples of the hydrolyzable groupinclude alkoxy, mercapto, halogen, amide, acetoxy, amino, isopropenoxygroups, and the like.

As the hydrolyzabile silyl group, for example, a halogenosilyl group, anacyloxysilyl group, an amidesilyl group, an aminoxysilyl group, analkenyloxysilyl group, an aminosilyl group, an oximesilyl group, analkoxysilyl group and a thio alkoxysilyl group are provided.

The silyl group is hydrolyzed and becomes a silanol group, which isdehydrated and condensed, and a siloxane bond generated.

In the present invention, the hydrolyzable silyl group in the siliconemodified acrylic resin is hydrolyzed via the polymerization reaction anddisappears, so there is no hydrolyzable silyl group in the siliconemodified acrylic resin. If the hydrolyzable silyl group remains, when itis used in making the recording ink, the storage properties maydeteriorate.

For confirming the non-usage of the hydrolyzable silyl group in thesilicone modified acrylic resin, a peak of ²⁹Si-NMR of the raw materialand a peak of ²⁹Si-NMR in a sample are compared to determine whether ornot the peak in the hydrolyzable silyl group has disappeared.

The resin fine-particles preferably have a volume average particlediameter of 10 nm to 300 nm, more preferably 40 nm to 200 nm. When thevolume average particle diameter is smaller than 10 nm, the resinemulsion has a higher viscosity. Therefore, it is sometimes difficult toobtain an ink viscosity dischargeable in an inkjet printer. When theaverage particle diameter is larger than 300 nm, the printer nozzle mayclog with the particles, causing discharge malfunction.

For the addition of the silicone modified acrylic resin fine-particlenot containing the hydrolyzable silyl group, it is preferable to add0.05 parts by mass to 1.2 parts by mass of silicone modified acrylicresin fine-particles not containing a hydrolyzable silyl group to 1 partby mass of pigment, and it is more preferable to add 0.2 parts by massto 1.0 parts by mass of the pigment. If the silicone modified acrylicresin fine-particles is less than 0.05 parts by mass, sufficientfixation may not be obtained, and if it is more than 1.2 parts by mass,sufficient image density may not be obtained.

Further, for the silicon (Si) quantity originating from the siliconemodified acrylic resin in the recording ink, 100 ppm to 400 ppm ispreferable, and 100 ppm to 300 ppm is more preferable. If the siliconamount is less than 50 ppm, a coating with excellent abrasion propertiesand marker resistance may not be obtained, and if it is more than 400ppm, the tendency of hydrophobicity becomes greater and the stability inthe aqueous ink may deteriorate.

Here, the silicon (Si) quantity in the recording ink can be measured,for example, using a high-frequency induction plasma emissionspectrometer.

For the minimum film forming temperature (MFT) of the silicone modifiedacrylic resin not containing the hydrolyzable silyl group, 20° C. orless is preferable, and 0° C. or less is more preferable. If the minimumfilm forming temperature is more than 20° C., sufficient fixation maynot be obtained, and when the printed portion is rubbed or traced with amarker pen, the pigment is removed and the recording medium may besmeared.

Here, the minimum film forming temperature (MFT) can be measured, forexample, using a film formation temperature meter.

—Penetrant—

As the penetrant, use is mad of a diol compound the carbon number ofwhich is 7 to 11. If the carbon number is less than 7, becausesufficient permeability cannot be obtained, a recording medium may besmeared with double-sided printing, or because the spread of the ink onthe recording medium is insufficient and pixel filling becomes worse,the reduction of letter quality or image density may occur. If thecarbon number is more than 11, the storage stability may deteriorate.

As the diol compound, for example, 2-ethyl-1,3-hexanediol or2,2,4-trimethyl-1,3-pentanediol is suitable.

For the addition of the diol compound, 0.1% by mass to 20% by mass ispreferable, and 0.5% by mass to 10% by mass is more preferable. If theaddition is too small, the permeability of the ink to the paperdeteriorates, and smearing may occur due to rubbing by a roller uponconveyance, or when reversing a recording surface of the recordingmedium for double-sided printing, and ink may become stuck to aconveying belt and smearing may occur, so it may be unresponsive tohigh-speed or double-sided printing. In the meantime, if the addition isexcessive, the printing dot diameter becomes larger, and the line widthof letters may become wider or the image definition may deteriorate.

—Colorant—

The colorant may be any one of pigments, dyes, and coloringfine-particles.

An aqueous dispersion of polymer fine-particles containing coloringmaterials is preferably used as the coloring fine-particles.

Here, the aforementioned “containing coloring materials” means eitherone or both of the state that coloring materials are sealed in polymerfine-particles and the state that coloring materials are adsorbed to thesurface of polymer fine-particles. All coloring materials mixed in therecording ink of the present invention are not necessarily sealed in oradhered to polymer fine-particles. The coloring materials may bedispersed in the emulsion as long as the efficacy of the presentinvention is not impaired. The coloring materials are not particularlylimited and may be appropriately selected according to the purpose aslong as they are insoluble or hardly soluble in water and can be adheredto the polymer.

Here, the aforementioned “insoluble or hardly soluble in water” meansthat 10 parts by mass or more of coloring materials are not dissolved in100 parts by mass of water at 20° C. Further, “soluble” means thatseparated or precipitated coloring materials are not visible at thesurface or bottom of an aqueous solution.

The average particle diameter of the polymer fine-particles containingcoloring materials (coloring fine-particles) in the ink is preferably0.16 μm or smaller.

The content of the coloring fine-particles in the recording ink is, bysolid content, preferably 8% by mass to 20% by mass, more preferably 8%by mass to 12% by mass.

The colorant may be dyes, such as water-soluble, oil-soluble, anddisperse dyes, and pigments, and the like. Oil-soluble and disperse dyesare preferable in view of excellent adsorption and sealable properties.However, pigments are preferably used in view of light stability ofobtained images.

The dyes are preferably dissolved in an organic solvent such as a ketonesolvent at a rate of 2 g/L or higher, more preferably at a rate of 20g/L to 600 g/L, in view of efficient impregnation into polymerfine-particles.

Water-soluble dye may be those classified as acidic, direct, basic,reactive, and food dyes in the color index and preferably has excellentwater resistance and light stability.

Examples of the acidic and food dyes include C.I. Acid Yellow 17, 23,42, 44, 79, 142; C.I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52,82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254, 289; C.I.Acid Blue 9, 29, 45, 92, 249; C.I. Acid Black 1, 2, 7, 24, 26, 94; C.I.Food Yellow 3, 4; C.I. Food Red 7, 9, 14; C.I. Food Black 1, 2, and thelike.

Examples of the Direct dye include C.I. Direct Yellow 1, 12, 24, 26, 33,44, 50, 86, 120, 132, 142, 144; C.I. Direct Red 1, 4, 9, 13, 17, 20, 28,31, 39, 80, 81, 83, 89, 225, 227; C.I. Direct Orange 26, 29, 62, 102;C.I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163,165, 199, 202; C.I. Direct Black 19, 22, 32, 38, 51, 56, ●71, 74, 75,77, 154, 168, 171, and the like.

Examples of the Basic dye include C.I. Basic Yellow 1, 2, 11, 13, 14,15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 64,65, 67, 70, 73, 77, 87, 91; C.I. Basic Red 2, 12, 13, 14, 15, 18, 22,23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70, 73,78, 82, 102, 104, 109, 112; C.I. Basic Blue 1, 3, 5, 7, 9, 21, 22, 26,35, 41, 45, 47, 54, 62, 65, 66, 67, 69, 75, 77, 78, 89, 92, 93, 105,117, 120, 122, 124, 129, 137, 141, 147, 155; C.I. Basic Black 2, 8, andthe like.

Examples of the reactive dye include C.I. Reactive Black 3, 4, 7, 11,12, 17; C.I. Reactive Yellow 1, 5, 11, 13, 14, 20, 21, 22, 25, 40, 47,51, 55, 65, 67; C.I. Reactive Red 1, 14, 17, 25, 26, 32, 37, 44, 46, 55,60, 66, 74, 79, 96, 97; C.I. Reactive Blue 1, 2, 7, 14, 15, 23, 32, 35,38, 41, 63, 80, 95, and the like.

The pigments are not particularly limited and may be appropriatelyselected according to the purpose. The pigments may be, for example,either inorganic or organic.

Examples of the inorganic pigments include titanium oxide, iron oxide,calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow,cadmium red, chrome yellow, carbon black, and the like. Among them,carbon black is preferable. Examples of the carbon black include thoseproduced by known methods such as contact, furnace, thermal methods, andthe like.

Examples of the organic pigments include azo pigments, polycyclicpigments, dye chelates, nitro pigments, nitroso pigments, aniline black,and the like. Among them, azo pigments and polycyclic pigments arepreferable. Examples of the azo pigments include azo lake, insoluble azopigments, condensed azo pigments, chelate azo pigments, and the like.Examples of the polycyclic pigments include phthalocyanine pigments,perylene pigments, perynone pigments, anthraquinone pigments,quinacridone pigments, dioxane pigments, indigo pigments, thioindigopigments, isoindolinone pigments, quinofuraron pigments, and the like.Examples of the dye chelates include basic dye chelates, acidic dyechelates, and the like.

The pigments are not particularly limited in color and may beappropriately selected according to the purpose. For example, black orcolor pigments can be used. They may be used individually or incombination of two or more.

Examples of the black pigments include carbon blacks (C.I. Pigment Black7), such as furnace black, lampblack, acetylene black, and channelblack, metals such as copper, iron (C.I. Pigment Black 11), and titaniumoxide, organic pigments such as aniline black (C.I. Pigment Black 1),and the like.

Among the color pigments, examples of yellow pigments include C.I.Pigment Yellow 1 (fast yellow G), 3, 12 (disazo yellow AAA), 13, 14, 17,23, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83 (disazoyellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128,138, 150, and 153, and the like.

Examples of magenta pigments include C.I. Pigment Red 1, 2, 3, 5, 17, 22(brilliant fast scarlet), 23, 31, 38, 48:2 (permanent red 2B (Ba)), 48:2(permanent red 2B (Ca)), 48:3 (permanent red 2B (Sr)), 48:4 (permanentred 2B (Mn)), 49:1, 52:2, 53:1, 57:1 (brilliant carmine 6B), 60:1, 63:1,63:2, 64:1, 81 (rhodamine 6G lake), 83, 88, 92, 101 (colcothar), 104,105, 106, 108 (cadmium red), 112, 114, 122 (dimethylquinacridone), 123,146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219,and the like.

Examples of cyan pigments include C.I. Pigment Blue 1, 2, 15 (copperphthalocyanine blue R), 15:1, 15:2, 15:3 (phthalocyanine blue G), 15:4,15:6 (phthalocyanine blue E), 16, 17:1, 56, 60, 63, and the like.

Examples of intermediate color, red, green, and blue, pigments includeC.I. Pigment Red 177, 194, 224, C.I. Pigment Orange 43, C.I. PigmentViolet 3, 19, 23, 37, C.I. Pigment Green 7, 36, and the like.

Among the pigments, self-dispersible color pigments that have at leastone hydrophilic group bound to the pigment surface directly or viaanother atomic group and are stably dispersed in the absence ofdispersant are preferably used. Consequently, a dispersant fordispersing the pigments, which is required in the prior art ink, isunnecessary. Among the self-dispersible color pigments, ionicself-dispersible color pigments are preferable. Anionic or cationicself-dispersible color pigments are preferable.

Examples of the anionic hydrophilic group include —COOM, —SO₃M, —PO₃HM,—PO₃M₂, —SO₂NH₂, and —SO₂NHCOR (in which M is a hydrogen atom, alkalimetal, ammonium, or organic ammonium; R is an alkyl group having 1 to 12carbon atoms, a phenyl group that may have a substituent, or a naphthylgroup that may have a substituent). Among them, color pigments having—COOM or —SO₃M bound to the surface are preferably used.

Examples of the alkali metal “M” in the hydrophilic group includelithium, sodium, potassium, and the like. Examples of the organicammonium include mono- or tri-methylammonium, mono- ortri-ethylammonium, and mono- or tri-methanolammonium. Among the anioniccolor pigments, a color pigment having —COONa bound to the surface maybe obtained for example by oxidizing a color pigment with sodiumhypochlorite, sulfonating, or reacting diazonium salt.

The cationic hydrophilic groups are, for example, preferably quaternaryammonium groups, more preferably the following quaternary ammoniumgroups. The pigments having any of these bound to the surface arepreferable color materials.

The -cationic self-dispersible carbon black having a hydrophilic groupmay be obtained for example by treating carbon black with3-amino-N-ethylpyridium bromide to bind an N-ethylpyridyl group havingthe following Structural Formula. Needless to say, the present inventionis not limited thereto.

The hydrophilic group may be bound to the carbon black surface viaanother atomic group in the present invention. Examples of the atomicgroup include an alkyl group having 1 to 12 carbon atoms, a phenyl groupthat may have a substituent, or a naphthyl group that may have asubstituent. Examples of the hydrophilic group bound to the carbon blacksurface via another atomic group include —C₂H₄COOM (in which M is analkali metal or a quaternary ammonium), -PhSO₃M (in which Ph is a phenylgroup; and M is an alkali metal or a quaternary ammonium), and—C₅H₁₀NH³⁺. Needless to say, the present invention is not limitedthereto.

Pigment dispersion using a pigment dispersant may be used in the presentinvention.

Examples of natural pigment dispersants among the pigment dispersant asthe hydrophilic polymers include plant polymers such as arabic gum,tragacanth gum, guar gum, karaya gum, locust bean gum, arabinogalactone,pectin, and quinceseed starch, seaweed polymers such as alginic acid,carrageenan, and agar, animal polymers such as gelatin, casein, albumin,and collagen, and microorganism polymers such as xanthein gum anddextran. Examples of semi-synthetic pigment dispersant include fibrouspolymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose,hydroxypropylcellulose, and carboxymethylcellulose, starch polymers suchas sodium carboxymethyl starch and sodium phosphate ester starch, andseaweed polymers such as sodium alginate, propylene glycol alginateester, and the like. Examples of pure synthetic pigment dispersantinclude vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone,and polyvinylmethyl ether, uncrosslinked polyacrylamide, polyacrylicacid and alkali metal salts thereof, acrylic resin such as water-solublestyreneacrylic resin, water-soluble styrenemaleic acid resin,water-soluble vinylnaphthaleneacrylic resin, water-solublevinylnaphthalenemaleic resin, polyvinylpyrrolidone, polyvinyl alcohol,alkali metal salt of fl-naphthalenesulfonic acid formarine condensate,polymers having a salt of a cationic functional group such as aquaternary ammonium and an amino group on the side chain, and naturalpolymer compounds such as shellac. Among them, those having a carboxylicacid group such as homopolymers of acrylic acid, methacrylic acid, andstyreneacrylic acid and copolymers of monomers having other hydrophilicgroups are particularly preferable polymer dispersants.

These copolymers preferably have a mass average molecular mass of 3,000to 50,000, more preferably 5,000 to 30,000, and further preferably 7,000to 15,000.

The mixture rate by mass of pigment to dispersant is preferably 1:0.06to 1:3, more preferably 1:0.125 to 1:3.

The addition rate of pigments as the colorant in the recording ink ispreferably 4% by mass to 15% by mass, more preferably 5% by mass to 12%by mass. Generally, the image concentration is increased and a higherimage quality is obtained as the pigment concentration is increased. Onthe other hand, adverse effects on fixing properties and reliabilityincluding stable discharge and clogging easily appear. However, thepresent invention ensures the fixing properties while maintaining thereliability including stable discharge and clogging even when thepigment addition rate is increased.

—Water-Soluble Organic Solvent—

The water-soluble organic solvents are not limited and may beappropriately selected according to the purpose. Examples of thewater-soluble organic solvent include polyvalent alcohols such asethylene glycol, diethylene glycol, triethylene glycol, polyethyleneglycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol,1,4-butane diol, 3-methyl-1,3-butandiol, 1,5-pentanediol,1,6-hexanediol, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol,1,2,3-butanetriol, petriol, 2,3-butane diol, tetraethylene glycol, and2-methyl-2,4-pentanediol, propylene glycol, dipropylene glycol,tripropylene glycol; polyvalent alcohol alkyl ethers such as ethyleneglycol monoethyl ether, ethylene glycol monobutyl ether, diethyleneglycol monomethyl ether, diethylene glycol monoethyl ether, diethyleneglycol monobutyl ether, tetraethylene glycol monomethyl ether, andpropylene glycol monoethyl ether; polyvalent alcohol aryl ethers such asethylene glycol monophenyl ether and ethylene glycol monobenzyl ether;nitrogen-containing heterocyclic compounds such asN-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone,1,3-dimethylimidazolidinone, and c-caprolactam; amides such asformamide, N-methylformamide, formamide, and N,N-dimethylformamide;amines such as monoethanolamine, diethanolamine, triethanolamine,monoethylamine, diethylamine, and triethylamine, sulfur-containingcompounds such as dimethylsulfoxide, sulfolane, and thiodiethanol,thiodiglycol, propylene carbonate, ethylene carbonate, and the like.These solvents may be used individually or in combination of two ormore. Among them, from the standpoint of obtaining excellent efficacy inpreventing jet characteristic failure due to solubility and moistureevaporation, glycerin, ethylene glycol, diethylene glycol, triethyleneglycol, propylene glycol, dipropylene glycol, tripropylene glycol,1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol,1,5-pentane diol, tetraethylene glycol, 1,6-hexanediol,2-methyl-2,4-pentane diol, polyethylene glycol, 1,2,4-butanetriol,1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone, N-methyl-2-pyrrolidone,or N-hydroxyethyl-2-pyrrolidone is suitable.

For the content of the water-soluble organic solvent in the recordingink, 15% by mass to 40% by mass is preferable and 20% by mass to 35% bymass is more preferable. If the content is too small, a nozzle is easilydried and discharge failure of droplets may occur, and if the content isexcessive, the ink viscosity becomes higher, and may exceed theappropriate viscosity range.

—Surfactant—

As the surfactant, an anionic surfactant, a cationic surfactant, anonionic surfactant, a fluorochemical surfactant and an ampholyticsurfactant are provided. These surfactants can be independently used orused by mixing two types or more.

Examples of the anionic surfactant include alkylallyl,alkylnaphthalenesulfonate, alkylphosphate, alkylsulfate, alkylsulfonate,alkylethersulfate, alkylsulfosuccinate, alkylestersulfate,alkylbenzenesulfonate, alkyldiphenyletherdisulfonate,alkylaryletherphosphate, alkylarylethersulfate,alkylaryletherestersulfate, olefinsulfonate, alkaneolefinsulfonate,polyoxyethylenealkyletherphosphate, polyoxyethylenealkylethersulficester salt, ethercarboxylate, sulfosuccinate, α-sulfo fatty acid ester,fatty acid salt, condensates of higher fatty acid and amino acid,polyoxyethylene alkyl ether acetate, dialkyl sulfosuccinate salt,naphthenate, and the like. Among these anionic surfactants,polyoxyethylene alkyl ether acetate or dialkyl sulfosuccinate salt ispreferable.

Examples of the nonionic surfactant include an acetylenic glycolicsurfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenylether, polyoxyethylene alky ester, polyoxyethylene sorbitan fatty acidester, and the like.

Examples of the cationic surfactant include alkylamine salt,dialkylamine salt, aliphatic amine salt, benzalkonium salt, quaternaryammonium salt, alkylpyridinium salt, imidazolinium salt, sulfonium salt,phosphonium, and the like.

Examples of the ampholytic surfactant include an imidazoline derivative,such as imidazolinium betaine, dimethylalkyllauryl betaine,alkylglycine, alkyldi (aminoethyl) glycine, and the like.

Examples of the fluorochemical surfactant include compounds expressedwith any of the following Structural Formulae (1) to (3).CF₃CF₂(CF₂CF₂)_(m)—CH₂CH₂O(CH₂CH₂O)_(n)H  Structural Formula (1)

in the Structural Formula (1), ‘m’ is an integer of 0 to 10, and ‘n’ isan integer of 1 to 40.

in the Structural Formula (2), ‘Rf’ is CF₃ or CF₂CF₃, ‘m’ is an integerof 6 to 25, ‘n’ is an integer of 1 to 4, and ‘p’ is an integer of 1 to4.

in the Structural Formula (3), ‘Rf’ is CF₃ or CF₂CF₃, and ‘q’ is aninteger of 1 to 6.

Examples of the compound having the Structural Formulae (1) to (3)include perfluoroalkylsulfonate, perfluoroalkylcarboxylate,perfluoroalkylphosphate, perfluoroalkylethyleneoxide adducts,perfluoroalkylbetaine, perfluoroalkylamineoxide compounds, and the like.

Commercially available fluorochemical surfactants can be used, includingSurflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (byAsahi Glass Co., Ltd.); FLUORAD FC-93, FC-95, FC-98, FC-129, FC-135,FC-170C, FC-430, FC-431, and FC4430 (by Sumitomo 3M Limited); MegafackF-470, F-1405, and F-474 (by Dainippon Ink & Chemicals Inc.); ZonylFS-300, FSN, FSN-100, FSO (by DuPont Kabushiki Kaisha); EFTOP EF-351,EF-352, EF-801, and EF-802 (by JEMCO Inc). Among them, Zonyl FS-300,FSN, FSN-100, and FSO (by DuPont Kabushiki Kaisha) are particularlypreferable in view of excellent reliability and improved colordevelopment.

Furthermore, the addition of the surfactant may be appropriatelyadjusted within a range in which the pigment can be stably dispersed andother efficacies of the present invention will not be lost.

—Aminopropanediol Compound—

The aminopropanediol compound is a water-soluble organic basic compoundand preferably, for example, aminopropanediol derivatives.

The aminopropanediol derivatives are not particularly limited and may beappropriately selected according to the purpose. Examples of theaminopropanediol derivatives include 1-amino-2,3-propane diol,1-methylamino-2,3-propanediol, 2-amino-2-methyl-1,3-propane diol,2-amino-2-ethyl-1,3-propane diol, and the like. Among them,2-amino-2-ethyl-1,3-propanediol is particularly preferable.

The addition rate of the aminopropanediol compound in the ink ispreferably 0.01% by mass to 10% by mass, more preferably 0.1% by mass to5.0% by mass, further preferably 0.1% by mass to 2.0% by mass. When theaddition rate is excessively high may increase pH, a disadvantage, suchas an increase of viscosity, may occur.

The other components are not particularly limited and may beappropriately selected according to the purpose. For example, pHadjusters, preservatives and fungicides, rust prevention age] its,antioxidants, ultraviolet absorbers, oxygen absorbers, and lightstabilizers may be used.

Examples of the preservatives and fungicides include1,2-benzisothiazoline-3-on, sodium dehydroacetate, sodium sorbate,2-pyridinethiol-1-oxide sodium, sodium benzoate, pentachlorophenolsodium, and the like.

The pH adjusters are not particularly limited and any substances may beused according to the purpose as long as they can be used to adjust thepH for 7 or higher without adverse effects on the ink to be prepared.

Examples of the pH adjusters include amines such as diethanolamine andtriethanolamine, alkali metal hydroxides such as lithium hydroxide,sodium hydroxide, and potassium hydroxide; ammonium hydroxide,quaternary ammonium hydroxide, quaternary phosphonium hydroxide, alkalimetal carbonates such as lithium carbonate, sodium carbonate, potassiumcarbonate, and the like.

Examples of the rust prevention agents include acidic sulfite, sodiumthiosulfate, anmone thioglycolate, diisopropylammoniumnitrite,pentaerythritol tetranitrate, dicyclohexylammoniumnitrite, and the like.

Examples of the antioxidants include phenolic antioxidants (includinghindered phenolic antioxidants), amine antioxidants, sulfurantioxidants, phosphorus antioxidants, and the like.

Examples of the phenolic antioxidants (including hindered phenolicantioxidants) include butylated hydroxyanisole,2,6-di-tert-butyl-4-ethylphenol,stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,2,2′-methylenebis(4-methyl-6-tert-butylphenol),2,2′-methylenebis(4-ethyl-6-tert-butylphenol),4,4′-butylidenebis(3-methyl-6-tert-butylphenol),1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,tetrakis[methylene-3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)propionate]methane,and the like.

Examples of the amine antioxidants include phenyl-β-naphthylamine,α-naphthylamine, N,N′-di-sec-butyl-p-phenyldiamine, phenothiazine,N,N′-diphenyl-p-phenylenediamine, 2,6-di-tert-butyl-p-cresol,2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-phenol,butylhydroxyanisole, 2,2′-methylenebis(4-methyl-6-tert-butylphenol),4,4′-butylidenebis(3-methyl-6-tert-butylphenol),4,4′-thiobis(3-methyl-6-tert-butylphenol),tetrakis[methylene-3(3,5-di-tert-butyl-4-dihydroxyphenyl)propionate]methane,1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, and the like.

Examples of the sulfur antioxidants include dilauryl3,3′-thiodipropionate, distearylthiopropionate,laurylstearylthiopropionate, dimyristyl 3,3′-thiodipropionate,distearyl, β,β′-thiodipropionate, 2-mercaptobenzoimidazole,dilaurylsulfide, and the like.

Examples of the phosphorus antioxidants include triphenylphosphite,octadecylphosphite, triisodecylphosphite, trilauryltrithiophosphite,trinonylphenylphosphite, and the like.

Examples of the ultraviolet absorbers include benzophenone,benzotriazole, salicylate, cyanoacrylate, nickel complex saltultraviolet absorbers, and the like.

Examples of the benzophenone ultraviolet absorbers include2-hydroxy-4-n-octoxybenzophenone, hydroxy-4-n-dodecyloxybenzophenone,2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,2,2′,4,4′-tetrahydroxybenzophenone, and the like.

Examples of the benzotriazole ultraviolet absorbers include2-(2′-hydroxy-5′-tert-octylphenyl)benzotriazole,2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(2′-hydroxy-4′-octoxyphenyl)benzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole, andthe like.

Examples of the salicylate ultraviolet absorbers includephenylsalicylate, p-tert-butylphenylsalicylate, p-octylphenylsalicylate,and the like.

Examples of the cyanoacrylate ultraviolet absorbers includeethyl-2-cyano-3,3′-diphenylacrylate,methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate,butyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate, and the like.

Examples of the nickel complex salt ultraviolet absorbers includenickelbis(octylphenyl)sulfide,2,2′-thiobis(4-tert-octylphelate)-n-butylaminenickel (II),2,2-thiobis(4-tert-octylphelate)-2-ethylhexylaminenickel (II),2,2′-thiobis(4-tert octylphelate)triethanolaminenickel (II), and thelike.

The recording ink of the present invention is produced by dispersing ordissolving at least water, a colorant, silicone modified acrylic resinfine-particles not containing a hydrolyzable silyl group and apenetrant, and in addition, other components, where necessary into aaqueous solvent, and by additionally by stirring and mixing the product,where necessary. The dispersing may be done by, for example, a sandmill, a homogenizer, a ball mill, a paint shaker, an ultrasonicdisperser, and the like. The stirring and mixing may generally be doneby, for example, a stirrer having stirring blades, a magnetic stirrer,or a high speed disperser.

Physical properties of the recording ink of the present invention arenot particularly limited and may be appropriately selected according tothe purpose. For example, the recording ink of the present inventionpreferably has the following ranges of solid content, viscosity, surfacetension, and pH.

For the solid content in the recording ink, 6% by mass to 20% by mass ispreferable and 8% by mass to 15% by mass is more preferable. If thesolid content is less than 6% by mass, sufficient image density may notbe obtainable after printing.

Here, the solid content in the ink in the present invention refersmainly to a colorant and resin fine-particle, which are insoluble inwater.

The viscosity is preferably 7 mPa·sec. to 20 mPa·sec., more preferably 5mPa·sec. to 10 mPa·sec., at 25° C. When the viscosity is higher than 20mPa·sec., it becomes difficult to ensure stable discharge.

The surface tension is preferably 25 mN/m to 55 mN/m at 20° C. When thesurface tension is lower than 25 mN/m, running ink is noticeable on therecording medium and stable jet may not be obtained. When it is higherthan 55 mN/m, the ink does not sufficiently infiltrate into therecording medium, which may prolong drying time.

The pH is, for example, preferably 7 to 10.

The coloring of the recording ink of the present invention is notparticularly limited and may be appropriately selected according to thepurpose. Yellow, magenta, cyan, and black may be used. An ink setcontaining a combination of two or more of these colorings can be usedin recording to form multicolor images. An ink set containing all thecolorings can be used in recording to form full color images.

The recording ink of the present invention can be successfully used inprinters provided with any types of inkjet heads including a piezo-typein which a piezoelectric element is used to pressurize ink in the inkpassage, a diaphragm forming the wall of the ink passage is deformed tochange the inner volume of the ink passage, thereby discharging inkdroplets (Japanese Patent Application Laid-Open (JP-A) No. 02-51734), athermal type in which an exothermic resistor is used to heat ink in theink passage to produce bubbles (Japanese Patent Application Laid-Open(JP-A) No. 61-59911), and an electrostatic type in which a diaphragmforming the wall of the ink passage and electrodes are placed at facingpositions and electrostatic force is produced between the diaphragm andthe electrodes to deform the diaphragm and change the inner volume ofthe ink passage, thereby discharging ink droplets (Japanese PatentApplication Laid-Open (JP-A) No. 06-71882).

The recording ink of the present invention may be preferably used in avariety of fields. It may be preferably used in image forming apparatus(such as printers) of an inkjet recording system. For example, therecording ink of the present invention can be used in a printer having afunction to heat recording papers and the recording ink to 50° C. to200° C. before, during, or after printing, thereby urging ink fixing.Particularly, the recording ink of the present invention may bepreferably used in the ink cartridge, ink record, inkjet recordingapparatus, and inkjet recording method of the present inventiondescribed hereinafter.

(Ink Cartridge)

The ink cartridge of the present invention comprises a containercontaining the recording ink of the present invention and otherappropriated selected members as required.

The container is not particularly limited and its shape, structure,size, and material are appropriately selected according to the purpose.Preferred embodiments include those at least having an ink pouch formedby aluminum laminated film, resin film, and the like.

The ink cartridge is hereinafter described with reference to FIGS. 1 and2. FIG. 1 is an illustration showing an embodiment of the ink cartridgeof the present invention. FIG. 2 is an illustration of the ink cartridgeof FIG. 1 including a case (exterior).

In an ink cartridge 200, as shown in FIG. 1, an ink pouch 241 is filledthrough an ink inlet 242. The ink inlet 242 is closed by fusion bondingafter the air is exhausted. An ink outlet 243 made of a rubber materialis pierced by a needle on the apparatus body for use, thereby the ink issupplied to the apparatus.

The ink pouch 241 is formed by a packaging member such as anon-permeable aluminum laminated film. The ink pouch 241 is housed in acartridge case 244 generally made of plastics as shown in FIG. 2 anddetachably mounted on various types of inkjet recording apparatus.

The ink cartridge of the present invention contains the recording ink(ink set) of the present invention. The ink cartridge of the presentinvention may be detachably mounted on variety types of inkjet recordingapparatus and it is particularly preferable that the ink cartridge ofthe present invention is detachably mounted on the inkjet recordingapparatus of the present invention described later.

(Inkjet Recording Apparatus and Inkjet Recording Method)

The inkjet recording apparatus of the present invention has at least anink drop discharging unit, and additionally has other unitsappropriately selected according to the purpose, such as an impulsegenerating unit or a controlling unit.

The inkjet recording method of the present invention at least comprisesthe ink drops discharging unit, and additionally comprises other unitsappropriately selected according to the purpose, such as an impulsegenerating unit, a controlling unit, and the like.

The inkjet recording method of the present invention is preferablyperformed in the inkjet recording apparatus of the present invention.The ink drops discharging step is preferably performed by the ink dropsdischarging unit. Further, the other steps are preferably performed bythe other units.

—Ink Drops Discharging Step and Ink Drops Discharging Unit—

The ink drops discharging step is a step of discharging the ink drops toform an image by applying impulse to the ink.

The ink drops discharging unit is a unit configured to discharge the inkdrops to form an image by applying impulse to the ink.

The ink drops discharging unit is not particularly limited, for example,include various nozzles for discharging ink.

It is preferable that the liquid chamber, fluid dragging part,diaphragm, and nozzle member of the nozzle head part be at least partlymade of materials containing at least either silicon or nickel.

The nozzle diameter of the nozzle head part is preferably 30 μm or lessand more preferably 1 μm to 20 μm.

It is preferable that subtanks for supplying ink be provided on theinkjet head and the ink is supplied to the subtanks from the inkcartridge via supply tubes.

The impulse may be generated by, for example, the impulse generationunit. The impulse is not particularly limited and may be appropriatelyselected according to the purpose. Examples of the impulse include heat(temperature), pressure, vibration, and light. These can be usedindividually or in combination or two or more. Among them, heat andpressure are preferable.

The impulse generation unit may be, for example, a heating apparatus, apressurizing apparatus, a piezoelectric element, a vibration generationapparatus, an ultrasonic oscillator, a light, and the like.Specifically, examples of the impulse generation unit include apiezoelectric actuator such as a piezoelectric element, a thermalactuator using an electrothermal conversion element such as anexothermic resistor to cause film boiling and, accordingly, phase changeof a liquid, a shape-memory alloy actuator using metal phase changes dueto temperature changes, an electrostatic actuator using electrostaticforce, and the like.

The aspect of the ink drops discharging is not particularly limited, andvaries depending on the type of the impulse. For example, when theimpulse is “heat,” thermal energy corresponding to recording signals isapplied to the ink in the recording head, for example, using a thermalhead, the thermal energy causes the ink to bubble, and the bubblepressure urges the ink to be discharged as ink droplets from the nozzlehole of the recording head. When the impulse is “pressure,” for example,an electric voltage is applied to a piezoelectric element bonded at aposition called a pressure chamber within the ink passage of therecording head, the piezoelectric element is bent and the pressurechamber is reduced in volume, thereby the ink is discharged as dropletsfrom the nozzle hole of the recording head.

The ink droplets before discharging preferably have a particle size of 3pl to 40 pl, a discharge jet speed of 5 m/sec. to 20 m/sec., a drivingfrequency of 1 kHz or higher, and a resolution of 300 dpi or higher.

It is preferable to have a reversing unit to reverse the recordingsurface of a recording medium and to enable double-sided printing. Asthe reversing unit, a conveying belt having an electrostatic force, aunit maintaining a recording medium due to air suction and a combinationof a conveying roller and spur are provided.

It is preferable to have an endless conveying belt, and a conveying unitconfigured to convey a recording medium while the surface of theconveying belt is electrified and the recording medium is maintained. Inthis case, it is especially preferable to electrify the conveying beltby applying an AC bias with f 1.2 kV to ±2.6 kV to anelectrically-charged roller.

The controlling unit is not particularly limited and may beappropriately selected according to the purpose as long as it is capableof controlling the operation of each unit. Examples of the controllingunit include devices such as a sequencer, a computer, and the like.

An embodiment of the inkjet recording method of the present inventionusing the inkjet recording apparatus of the present invention isdescribed hereinafter, with reference to the drawings. An inkjetrecording apparatus shown in FIG. 3 comprises apparatus body 101, feedertray 102 attached to the apparatus body 101 for feeding papers, paperoutput tray 103 attached to the apparatus body 101 for receiving paperson which images are recorded (formed), and an ink cartridge mountingpart 104. Operation part 105 having operation keys and indicators isprovided on the top surface of the ink cartridge mounting part 104. Theink cartridge mounting part 104 has front cover 115 that can be openedand/or closed to remove and/or place ink cartridges 201.

As shown in FIGS. 4 and 5, carriage 133 is supported slidably in thescan direction by guide rod 131 that is a guide member laid across notshown right and left side plates and stay 132 and moved by a main motor(not shown) in the arrowed directions in FIG. 5 for scanning within theapparatus body 101.

Recording heads 134 consisting of four inkjet recording heads thatdischarge yellow (Y), cyan (C), magenta (M), and black (B) recording inkdroplets, respectively, have ink discharge ports arranged in theintersecting direction with the main scanning direction and they areplaced with their ink discharge direction downward.

Inkjet recording heads constituting the recording heads 134 are providedwith an energy generation unit for discharging recording ink such as apiezoelectric actuator such as an piezoelectric element, a thermalactuator using an electrothermal conversion element such as anexothermic resistor to cause film boiling and, accordingly, phase changeof a liquid, a shape-memory alloy actuator using metal phase changes dueto temperature changes, and an electrostatic actuator usingelectrostatic force.

The carriage 133 is provided with subtanks 135 for supplying each colorink to the recording heads 134. The subtanks 135 are filled with therecording ink of the present invention from the ink cartridge 201 of thepresent invention mounted in the ink cartridge mounting part 105 via anot-shown recording ink supply tube.

On the other hand, a paper feed part for feeding paper 142 stuck onpaper load part (platen) 141 of the feed tray 102 comprises a half-moonroller (feed roller 143) that separates and supplies the paper 142 fromthe paper load part 141 one by one and separation pad 144 that faces thefeed roller 143 and is made of a large friction coefficient material.The separation pad 144 is biased toward the feed roller 143.

A conveying part for conveying the paper 142 supplied from the feed partunderneath the recording heads 134 comprises a conveying belt 151 forelectrostatically adsorbing and conveying the paper 142, counter roller152 for conveying the paper 142 sent from the paper feed part via guide145 by clamping it together with the conveying belts 151, conveyingguide 153 for turning the paper 142 sent nearly vertically by 90° so asto lay it on the conveying belt 151, and leading end pressure roller 155that is biased toward the conveying belt 151 by presser member 154.Charging roller 156 that is a charging unit for charging the surface ofthe conveying belt 151 is also provided.

The conveying belt 151 is an endless belt, being placed over conveyingroller 157 and a tension roller 158 and running around in the beltconveying direction. For example, the conveying belt 151 has a frontlayer that is a paper adsorbing surface made of a dragging-uncontrolledresin, for example a copolymer of tetrafluoroethylene and ethylene(ETFE), having a thickness of 40 μm and a back layer (an intermediatedragging layer or an earth layer) made of the same material as the frontlayer, but dragging-controlled with carbon. Guide member 161 is providedbehind the conveying belt 151 at the corresponding position to theprinting area by the recording heads 134. An output part for dischargingthe paper 142 on which recording was done by the recording heads 134comprises separation click 171 for separating the paper 142 from theconveying belt 151, paper output roller 172, and paper output roller173. Paper output tray 103 is disposed below paper output roller 172.

Double-side feed unit 181 is detachably mounted in the back of theapparatus body 101. The double-side feed unit 181 takes in the paper 142that is moved backward as the conveying belt 151 is rotated in thereverse direction, turns it over, and feeds it again between the counterroller 152 and the conveying belt 151. Manual feeder 182 is provided onthe top surface of the double-side feed unit 181.

In this inkjet recording apparatus, the paper 142 is separated and fedfrom the paper feed part one by one. Being fed vertically, the paper 142is guided by the guide 145 and conveyed between the conveying belt 151and the counter roller 152. Then, it is guided by the conveying guide153 at the leading end and is pressed against the conveying belt 151 bythe leading end pressure roller 155 to change the convey directionsubstantially by 90°.

Meanwhile, the conveying belt 157 is charged by the charging roller 156and the paper 142 is electrostatically adsorbed and conveyed by theconveying belt 151. Then, the recording heads 134 are driven accordingto image signals while the carriage 133 is moved. Ink droplets aredischarged on the paused paper 142 for recording one-line. Then, thepaper 142 is conveyed by a certain rate for recording the next line.Receiving a recording end signal or a signal indicating the rear end ofthe paper 142 has reached the recording area, the recording operation isterminated and the paper 142 is discharged to the paper output tray 103.

When it is detected that the remaining amount of the recording ink inthe subtank 135 is nearly to the end, a certain amount of recording inkis supplied to the subtank 135 from the ink cartridge 201.

In this inkjet recording apparatus, when the recording ink in the inkcartridge 201 of the present invention is used up, the case of the inkcartridge 201 is disassembled and only the ink pouch contained thereincan be exchanged. The ink cartridge 201 allows for stable recording inksupply even in a vertical and front mounting structure. Therefore, whenthe apparatus body 101 is installed with the top being blocked bysomething, for example, the ink cartridge 210 can be housed in a rack.Even if something is placed on the top surface of the apparatus body101, the ink cartridge 201 can be easily replaced.

Here, the explanation is made with reference to an application in aserial type (shuttle type) inkjet recording apparatus in which thecarriage scans is described. A line type inkjet recording apparatushaving a line head is also applicable.

The inkjet recording apparatus and inkjet recording method of thepresent invention are applicable to various recording in an inkjetrecording system. For example, the inkjet recording apparatus and inkjetrecording method of the present invention can be particularly preferablyapplied to inkjet recording printers, facsimiles, copy machines, andprinter/fax/copy complex machines.

An inkjet head to which the present invention is applied is describedhereinafter.

FIG. 6 is an enlarged view of the core part of the inkjet head accordingto an embodiment of the present invention. FIG. 7 is an enlargedcross-sectional view of the core part of the same head in theinter-channel direction.

This inkjet head comprises frame 10 having cutouts serving as an inksupply port (not shown) and a common liquid chamber 1 b, passage plate20 having cutouts serving as fluid dragging part 2 a and pressurizedliquid chamber 2 b and communication port 2 c that communicates tonozzle 3 a, diaphragm 60 having raised part 6 a, diaphragm part 6 b, andink inflow port 6 c, laminated piezoelectric element 50 connected to thediaphragm 60 via adhesive layer 70, and base 40 on which the laminatedpiezoelectric element 50 is fixed.

The base 40 is made of barium titanate ceramics, on which two rows oflaminated piezoelectric element 50 are arranged and connected.

The piezoelectric element 50 consists of alternately laminatedpiezoelectric layers of lead zirconate titanate (PZT) having a thicknessof 10 μm to 50 μm per layer and internal electrode layers of silverpalladium (AgPd) having a thickness of several μm per layer. Theinternal electrode layers are connected to external electrodes at bothends.

The laminated piezoelectric element 50 is divided into a comb-like shapeby half-cut dicing, having driving parts 5 f and supporting parts(non-driving part) 5 g every other division. The exterior of theexternal electrodes is processed, for example notched, for limiting onlength, thereby being divided by half-cut dicing. Multiple separateelectrodes are formed. Not divided by dicing, the other is conductiveand serves as a common electrode.

A FPC8 is soldered to the individual electrodes of the driving part. Thecommon electrode is turned in an electrode layer provided at the end ofthe laminated piezoelectric layer and connected to the Gnd electrode ofthe FPC8. An un-shown driver IC is mounted on the FPC8 to control theapplication of driving voltage to the driving part 5 f.

As for the diaphragm 60, thin film diaphragm part 6 b, island-shapedraised part (island part) 6 a formed at the center of the diaphragm part6 b and connected to the laminated piezoelectric element 50 serving asthe driving parts 5 f, a thick part including beams to be connected tothe supporting part, and an opening serving as in ink inflow port 6 care formed by electroforming two nickel plated films. The diaphragm hasa thickness of 3 μm and a width (one side) of 35 μm.

The connections between the island part 6 a of the diaphragm 60 and themovable parts 5 f of the laminated piezoelectric element 50 and betweenthe diaphragm 50 and the frame 10 are made by patterning the adhesivelayer 70 including a gap material.

The passage plate 20 is made of a silicon mono-crystalline substrate, inwhich cutouts serving as liquid dragging part 2 a and pressurized liquidchamber 2 b and a through-hole provided at the corresponding position tothe nozzle 3 a and serving as communication port 2 c are patterned byetching.

The remaining part after the etching serves as a partition wall 2 d ofthe pressurized liquid chamber 2 b. In this head, a part etched in asmaller width serves as the liquid dragging part 2 a.

The nozzle plate 30 is made of a metal material such as a nickel platedfilm formed by electroforming and has a number of nozzles 3 a serving asfine discharge openings for discharging ink droplets. The nozzle 3 a hasa horn-like (substantially cylindrical or substantially truncated cone)internal shape (inner shape). The nozzle 3 a has a diameter ofapproximately 20 μm to 35 μm at the ink droplets discharge side. Thenozzle pitch in each row is 150 dpi.

The ink discharging surface (nozzle front side) of the nozzle plate 30is provided with a water-repellent finish layer 3 b having a not shownwater-repellent finish surface. A water-repellent finish film selectedaccording to ink's physical properties such as PTFE-Ni eutectoid platingand electrodeposition of fluororesin, deposition of volatilefluororesin, silicone resin and fluororesin solvent application andbaking can be provided to stabilize ink droplet shapes and dischargingproperty and, thus, ensure a high image quality. Among them, for examplemany fluororesins are known; excellent water-repellency can be obtainedby depositing modified perfluoropolyoxethane (by Daikin Industries, Ltd,trade name: Optool DSX) to a thickness of 30 Å to 100 Å.

The frame 10 in which cutouts serving as an ink supply inlet and acommon liquid chamber 1 b are formed is made by molding a resin.

In an inkjet head having the above structure, a driving waveform (10V to50V pulse voltage) is applied to the driving part 5 f according torecording signals. The driving part 5 f is shifted in the laminationdirection. The pressurized liquid chamber 2 b is pressurized via thediaphragm 30 and the pressure is increased, thereby ink droplets aredischarged through the nozzle 3 a.

After the ink droplets discharge is completed, the ink pressure in thepressurized liquid chamber 2 b is decreased. The inertia ink flow anddriving pulse discharge process causes negative pressure within thepressurized liquid chamber 2 b, leading to the ink supply step.Meanwhile, the ink supplied from the ink tank enters the common liquidchamber 1 b and further fills the pressurized liquid chamber 2 b fromthe common liquid chamber 1 b via the ink inflow port 6 c and fluiddragging part 2 a.

The fluid dragging part 2 a effectively attenuates residual pressurefluctuation while it stands against recharging (refilling) due tosurface tension. Appropriately selected dragging part balances residualpressure attenuation with refilling time and shortens the transitiontime to the next ink droplets discharge operation (driving cycle).

(Ink Record)

The ink record recorded by the inkjet recording apparatus and inkjetrecording method of the present invention is the ink record of thepresent invention. The ink record of the present invention comprisesimages formed on recording media using the recording ink of the presentinvention.

The recording media are not particularly limited and may beappropriately selected according to the purpose. Examples of therecording media include regular papers, glossy papers, special papers,cloths, films, and OHP sheets. These can be used individually or incombination of two or more.

The ink record has high quality, no running ink, and excellent temporalstability, thereby being preferably used in various applications asdocuments in which various texts and images are recorded.

EXAMPLE

Examples of the present invention are described hereinafter. However,the present invention is not limited to these examples. All percentagesand parts are by mass unless indicated otherwise.

Preparation Example 1

—Preparation of Surface-Treated Carbon Black Pigment Dispersion—

The addition of 90 g of carbon black, where the CTAB specific surfacearea is 150 m²/g and the DBP oil absorption is 100 ml/100 g, to 3,000 mlof 2.5 N sodium sulfate solution was added, and stirred at 60° C., 300rpm, and oxidation accomplished by reaction for 10 hours. The reactionliquid was filtered; the filtered carbon black neutralized with a sodiumhydroxide solution; and ultra-filtration accomplished. The obtainedcarbon black was rinsed with water and dried, and dispersed in thepurified water so as to form 20% by mass of the pigment concentration,by which process the surface-treated carbon black pigment dispersion wasprepared.

Preparation Example 2

—Preparation of Surface-Treated Yellow Pigment Dispersion—

A yellow pigment was produced where C.I. Pigment Yellow 128 wasplasma-treated at low temperature and a carboxyl group was introduced. Aliquid where yellow pigment was dispersed in the deionized water wasde-mineralized and concentrated with an ultra-filter, and a yellowpigment dispersion of 15% by mass of pigment concentration was prepared.

Preparation Example 3

—Preparation of Surface-Treated Magenta Pigment—

Magenta pigment where a carboxyl group was introduced was similarlyprepared in Preparation example 2 except that C.I. Pigment Yellow 128was replaced with C.I. Pigment Red 122.

The obtained surface-treated magenta pigment was easily dispersed in aaqueous solvent during stirring.

Preparation Example 4

—Preparation of Surface-Treated Cyan Pigment—

Cyan pigment where a carboxyl group was introduced was similarlyprepared in Preparation example 2 except that C.I. Pigment Yellow 128was replaced with C.I. Pigment Cyan 15:3.

The obtained surface-treated cyan pigment was easily dispersed in anaqueous solvent during stirring.

Synthesis Example 1

—Synthesis of Polymer Dispersion—

First, the inside of a 1 L flask equipped with a mechanical stirrer, athermometer, a nitrogen gas inlet tube, a reflux tube and a droppingfunnel was sufficiently purged, with nitrogen gas. Then 11.2 g ofstyrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate, 4.0 g ofpolyethylene glycol methacrylate, 4.0 g of styrene macromer(manufactured by Toagosei Co., Ltd., product name: AS-6) and 0.4 g ofmercaptoethanol were introduced and heated to 65° C. Next, a mixedsolution with 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g oflauryl methacrylate, 36.0 g of polyethylene glycolmethacrylate, 60.0 gof hydroxyethylmethacrylate, 36.0 g of styrene macromer (manufactured byToagosei Co., Ltd., product name: AS-6), 3.6 g of mercaptoethanol, 2.4 gof azobis dimethyl valeronitrile and 18 g of methyl ethyl ketone wastitrated into the flask over 2.5 hours. After the titration wascompleted, a mixed solution with 0.8 g of azobis dimethyl valeronitrileand 18 g of methyl ethyl ketone was titrated into the flask for 0.5hour. After maturing at 65° C. for 1 hour, 0.8 g of azobis dimethylvaleronitrile was added, and the product was additionally matured for 1hour. After the reaction was completed, 364 g of methyl ethyl ketone wasadded, and 800 g of polymer solution of 50% by mass was obtained.

Preparation Example 5

—Preparation of Polymer Fine-Particles Dispersion ContainingPhthalocyanine Pigment—

After 28 g of the polymer solution prepared in Synthesis example 1, 26 gof phthalocyanine pigment, 13.6 g of 1 mol/L potassium hydroxidesolution, 20 g of methyl ethyl ketone and 30 g of deionized water weresufficiently stirred and mixed using three roll mills.

The obtained paste was added to 200 g of deionized water, and afterbeing sufficiently stirred, methyl ethyl ketone and water were distilledaway using an evaporator, and a cyan polymer fine-particles dispersionwas prepared.

Preparation Example 6

—Preparation of Polymer Fine-Particles Dispersion Containing DimethylQuinacridon Pigment—

A magenta polymer fine-particles dispersion was similarly prepared inPreparation example 5 except that the phthalocyanine pigment wasreplaced with C.I. Pigment Red 122.

Preparation Example 7

—Preparation of Polymer Fine-Particles Dispersion Containing MonoazoYellow Pigment—

A yellow polymer fine-particles dispersion was similarly prepared inPreparation example 5 except that the phthalocyanine pigment wasreplaced with a pigment C.I. Pigment Yellow 74.

Preparation Example 8

—Preparation of Polymer Fine-Particles Dispersion Containing CarbonBlack Pigment—

A black polymer fine-particles dispersion was similarly prepared inPreparation example 5 except for changing the phthalocyanine pigment wasreplaced with a carbon black.

Synthesis Example 2

—Synthesis of Silicone Modified Acrylic Resin Fine-Particles NotContaining Reactive Silyl Group—

First, the inside of a flask, which was equipped with a mechanicalstirrer, a thermometer, a nitrogen gas inlet tube, a flux tube and adropping funnel was sufficiently purged with nitrogen gas. Then, 10 g ofAqualon RN-20 (manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.), 1 g ofpotassium persulfate and 286 g of purified water were introduced andheated to 65° C. Next, a mixed solution with 150 g of methylmethacrylate, 100 g of acrylic acid-2-ethylhexyl, 20 g of acrylic acid,20 g of vinyltriethoxysilane, 10 g of Aqualon RN-20 (manufactured byDai-Ichi Kogyo Seiyaku Co., Ltd.), 4 g of potassium persulfate and 398.3g of purified water was titrated into the flask over 2.5 hours. Afterheating and maturing at 80° C. for an another 3 hours, the product wascooled down and the pH adjusted to 7 to 8 with potassium hydroxide.

A peak of ²⁹Si-NMR of the obtained silicone modified acrylic resinfine-particles was compared with a peak of ²⁹Si-NMR of the raw material,and because the peak by the hydrolyzable silyl group disappeared, it wasconfirmed that there was no reactive silyl group.

<Measurement Conditions for ²⁹Si-NMR>

Equipment: NMR (solid measurement)

SR-MAS (Sweat Resin-Magic Angle Spinning)—²⁹Si-NMR measurement wasconducted.

Test tube: made from zirconia

Cap: made from Daifron

The volume average particle diameter (D50%) of the obtained siliconemodified acrylic resin fine-particles not containing a reactive silylgroup measured with a particle diameter analyzer (Microtrac UPAmanufactured by NIKKISO Co., Ltd.) was 130 nm. Further, the minimum filmforming temperature (MFT) measured by the film formation temperaturemeter was 0° C.

Synthesis Example 3

—Synthesis of Silicone Modified Acrylic Resin Fine-Particles NotContaining Reactive Silyl Group—

Firsts, the inside of a flask equipped with a mechanical stirrer, athermometer, a nitrogen gas inlet tube, a flux tube and a droppingfunnel was sufficiently purged with nitrogen gas. Then, 10 g of AqualonRN-20 (manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.), 1 g ofpotassium persulfate and 286 g of purified water were introduced andheated to 65° C. Next, a mixed solution with 150 g of methylmethacrylate, 100 g of acrylic acid-2-ethylhexyl, 20 g of acrylic acid,40 g of hexyltrimethoxysilane, 10 g of Aqualon. RN-20 (manufactured byDai-Ichi Kogyo Seiyaku Co., Ltd.), 4 g of potassium persulfate and 398.3g of purified water was titrated into the flask over 3 hours. Aftermaturing by heating at 80° C. for another 3 hours, the product wascooled down and the pH adjusted to 7 to 8 with potassium hydroxide.

With regard to the obtained silicone modified acrylic resinfine-particles, as with Synthesis example 2, a peak of ²⁹Si-NMR wascompared with a peak of ²⁹Si-NMR of the raw material, and because thepeak by the hydrolyzable silyl group disappeared, it was confirmed thatthere was no reactive silyl group.

The volume average particle diameter (D50%) of the obtained siliconemodified acrylic resin fine-particles not containing a reactive silylgroup measured with the particle diameter analyzer (Microtrac UPAmanufactured by NIKKISO Co., Ltd.) was 148 nm. Further, the minimum filmforming temperature (MFT) measured by the film formation temperaturemeter was 0° C.

Synthesis Example 4

—Synthesis of Silicone Modified Acrylic Resin Fine-Particles ContainingReactive Silyl Group—

In order to double-check an example described in Japanese PatentApplication Laid-Open (JP-A) No. 6-157861, the silicone modified acrylicresin fine-particles containing the reactive silyl group wassynthesized.

First, the inside of a flask equipped with a mechanical stirrer, athermometer, a nitrogen gas inlet tube, a flux tube and a droppingfunnel was sufficiently purged with nitrogen gas. Then, 100 g ofpurified water, 3 g of sodium dodecyl benzenesulfonate and 1 g ofpolyethylene glycol nonylphenylether were introduced; 1 g of ammoniumpersulfate and 0.2 g of sodium hydrogensulfite were added; and thetemperature increased to 60° C. Next, 30 g of butyl acrylate, 40 g ofmethyl methacrylate, 19 g of butyl methacrylate, 10 g of vinylsilanetriol potassium salt and 1 g of 3-metacryloxypropylmethyldimethoxysilane were titrated into the flask over 3 hours. Apolymerization reaction liquid at this time was adjusted to be pH 7 withan ammonium solution, and polymerization was performed.

With regard to the obtained silicone modified acrylic resinfine-particles, as similar to Synthesis example 2, a peak of ²⁹Si-NMRwas compared with a peak of ²⁹Si-NMR of the raw material, and becausethe peak by the hydrolyzable silyl group appeared, it was confirmed thatthere was reactive silyl group.

The volume average particle diameter (D50%) of the obtained siliconemodified acrylic resin fine-particles containing a reactive silyl groupmeasured with the particle diameter analyzer (Microtrac UPA manufacturedby NIKKISO Co., Ltd.) was 160 nm. Further, the minimum film formingtemperature (MFT) measured by the film formation temperature meter was0° C.

Synthesis Example 5

—Synthesis of Silicone Modified Acrylic Resin Fine-Particles NotContaining Reactive Silyl Group—

First, the inside of a flask equipped with a mechanical stirrer, athermometer, a nitrogen gas inlet tube, a flux tube, and a droppingfunnel was sufficiently purged with nitrogen gas. Then, 10 g of AqualonRN-20 (manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.), 1 g ofpotassium persulfate and 286 g of purified water were introduced andheated to 65° C. Next, a mixed solution with 150 g of methylmethacrylate, 100 g of acrylic acid-2-ethylhexyl, 20 g of acrylic acid,40 g of hexyltrimethoxysilane, 10 g of Aquaion RN-20 (manufactured byDai-Ichi Kogyo Seiyaku Co., Ltd.), 4 g of potassium persulfate and 398.3g of purified water was titrated into the flask over 3 hours. Aftermaturing by heating at 80° C. for another 3 hours, the product wascooled down and the pH adjusted to 7 to 8 with potassium hydroxide.

With regard to the obtained silicone modified acrylic resinfine-particles, as with Synthesis example 2, a peak of ²⁹Si-NMR wascompared with a peak of ²⁹Si-NMR of the raw material, and because thepeak by the hydrolyzable silyl group disappeared, it was confirmed thatthere was no reactive silyl group.

The volume average particle diameter (D50%) of the obtained siliconemodified acrylic resin fine-particles not containing a reactive silylgroup measured with the particle diameter analyzer (Microtrac UPAmanufactured by NIKKISO Co., Ltd.) was 310 nm. Further, the minimum filmforming temperature (MFT) measured by the film formation temperaturemeter was 0° C.

Synthesis Example 6

—Synthesis of Silicone Modified Acrylic Resin Fine-Particles NotContaining Reactive Silyl Group—

First, the inside of a flask equipped with a mechanical stirrer, athermometer, a nitrogen gas inlet tube, a flux tube and a droppingfunnel as sufficiently purged with nitrogen gas. Then, 30 g of AqualonRN-20 (manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.), 1 g ofpotassium persulfate and 286 g of purified water were introduced andheated to 65° C. Next, a mixed solution with 150 g of methylmethacrylate, 100 g of acrylic acid-2-ethylhexyl, 20 g of acrylic acid,20 g of vinyltriethoxysilane, 30 g of Aqualon RN-20 (manufactured byDai-Ichi Kogyo Seiyaku Co., Ltd.), 4 g of potassium persulfate and 400 gof purified water was titrated into the flask over 2.5 hours. Aftermaturing by heating at 80° C. for another 3 hours, the product wascooled down and the pH adjusted to 7 to 8 with potassium hydroxide.

With regard to the obtained silicone modified acrylic resinfine-particles, as with Synthesis example 2, a peak of ²⁹Si-NMR wascompared with a peak of ²⁹Si-NMR of the raw material, and because thepeak by the hydrolyzable silyl group disappeared, it was confirmed thatthere was no reactive silyl group.

The volume average particle diameter (D50%) of the obtained siliconemodified acrylic resin fine-particles not containing a reactive silylgroup measured with the particle diameter analyzer (Microtrac UPAmanufactured by NIKKISO Co., Ltd.) was 48 nm. Further, the minimum filmforming temperature (MFT) measured by the film formation temperaturemeter was 0° C.

Synthesis Example 7

—Synthesis of Silicone Modified Acrylic Resin Fine-Particles NotContaining Reactive Silyl Group—

First, the inside of a flask equipped with a mechanical stirrer, athermometer, a nitrogen gas inlet tube, a flux tube and a droppingfunnel was sufficiently purged with nitrogen gas. Then, 130 g of AqualonRN-20 (manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.), 1 g ofpotassium persulfate and 286 g of purified water were introduced andheated to 65° C. Next, a mixed solution with 150 g of methylmethacrylate, 100 g of acrylic acid-2-ethylhexyl, 20 g of acrylic acid,20 g of vinyltriethoxysilane, 30 g of Aqualon RN-20 (manufactured byDai-Ichi Kogyo Seiyaku Co., Ltd.), 4 g of potassium persulfate and 400 gof purified water was titrated into the flask over 2.5 hours. Aftermaturing by heating at 80° C. for another 3 hours, the product wascooled down and the pH adjusted to 7 to 8 with potassium hydroxide.

With regard to the obtained silicone modified acrylic resinfine-particles, as with Synthesis example 2, a peak of ²⁹Si-NMR wascompared with a peak of ²⁹Si-NMR of the raw material, and because thepeak by the hydrolyzable silyl group disappeared, it was confirmed thatthere was no reactive silyl group.

The volume average particle diameter (D50%) of the obtained siliconemodified acrylic resin fine-particles not containing a reactive silylgroup measured with the particle diameter analyzer (Microtrac UPAmanufactured by NIKKISO Co., Ltd.) was 10 nm. Further, the minimum filmforming temperature (MFT) measured by the film formation temperaturemeter was 0° C.

Example 1

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 5.0% by mass (as solid)    -   Diethylene glycol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   2-pyrrolidone . . . 2.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 56.0% by mass

Example 2

—Production of Yellow Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 um of average bore diameter, thereby produced the ink

<Ink Composition>

-   -   Yellow pigment dispersion in Preparation example 2 . . . 6.0% by        mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 5.0% by mass (as solid)    -   1,5-pentanediol . . . 20.0% by mass    -   Glycerin . . . 5.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 61.0% by mass

Example 3

—Production of Magenta Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Magenta pigment dispersion in Preparation example 3 . . . 7.0%        by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 3.0% by mass (as solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   N-methyl-2-pyrrolidone . . . 3.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 60.0% by mass

Example 4

—Production of Cyan Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Cyan pigment dispersion in Preparation example 4 . . . 6.0% by        mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 5.0% by mass (as solid)    -   1,5-pentanediol . . . 20.0% by mass    -   Glycerin . . . 5.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 61.0% by mass

Example 5

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 Ara of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon Black pigment polymer dispersion in Preparation example 8        . . . 10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 2.0% by mass (as solid)    -   1,6-hexanediol . . . 15.0% by mass    -   Glycerin . . . 7.0% by mass    -   2-pyrrolidone . . . 2.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 61.0% by mass

Example 6

—Production of Cyan Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Cyan pigment dispersion in Preparation example 5 . . . 7.0% by        mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 3.0% by mass (as solid)    -   1,5-pentanediol . . . 16.0% by mass    -   Glycerin . . . 6.0% by mass    -   N-methyl-2-pyrrolidone . . . 5.0% by mass    -   Surfactant (Softanol EP 7025 manufactured by Nippon Shokubai        Co., Ltd.) . . . 2.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 59.0% by mass

Example 7

—Production of Magenta Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Magenta pigment polymer dispersion in Preparation example 6 . .        . 6.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 3.0% by mass (as solid)    -   1,3-butanediol . . . 20.0% by mass    -   Glycerin . . . 5.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 2.0% by mass    -   2-ethyl-1,3-hexanediol . . . 3.0% by mass    -   Deionized water . . . 61.0% by mass

Example 8

—Production of Yellow Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Yellow pigment polymer dispersion in Preparation example 7 . . .        5.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 2.0% by mass (as solid)    -   1,5-pentanediol . . . 20.0% by mass    -   Glycerin . . . 6.0% by mass    -   N-methyl-2-pyrrolidone . . . 3.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 2.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 60.0% by mass

Example 9

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 10.0% by mass (as solid)    -   Diethylene glycol . . . 16.0% by mass    -   Glycerin . . . 8.0% by mass    -   2-pyrrolidone . . . 2.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 2.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 1.0% by mass    -   Deionized water . . . 51.0% by mass

Example 10

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        8.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 4.0% by mass (as solid)    -   3-methyl-1,3-butanediol . . . 16.0% by mass    -   Glycerin . . . 8.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 2.0% by mass    -   2-ethyl-1,3-hexanediol . . . 1.0% by mass    -   1-amino-2,3-propanediol . . . 0.5% by mass    -   Deionized water . . . 60.5% by mass

Example 1

—Production of Yellow Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Yellow pigment dispersion in Preparation example 2 . . . 6.0% by        mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 1.0% by mass (as solid)    -   1,6-hexanediol . . . 21.0% by mass    -   2-pyrrolidone: . . . 2.0% by mass    -   Glycerin . . . 7.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 60.0% by mass

Example 12

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        13.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 8.0% by mass (as solid)    -   Diethylene glycol . . . 14.0% by mass    -   Glycerin . . . 7.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 55.0% by mass

Example 13

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 0.5% by mass (as solid)    -   3-methyl-1,3-butanediol . . . 16.0% by mass    -   Glycerin . . . 5.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 65.5% by mass

Example 14

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 3 . . . 8.0% by mass (as solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 55.0% by mass

Example 15

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 5 . . . 8.0% by mass (as solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 55.0% by mass

Example 16

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 6 . . . 5.0% by mass (as solid)    -   1,6-hexanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   2-pyrrolidone . . . 2.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 56.0% by mass

Example 17

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 7 . . . 5.0% by mass (as solid)    -   1,6-hexanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   2-pyrrolidone . . . 2.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 56.0% by mass

Example 18

—Production of Cyan Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 um of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Cyan pigment polymer dispersion in Preparation example 4 . . .        6.0% by mass (as solid)    -   Aquabrid Asi 91 (manufactured by Daicel Chemical Industries,        Ltd., silicone modified acrylic resin: MFT=25 CC) . . . 4.0% by        mass (as solid)    -   1,6-hexanediol . . . 20.0% by mass    -   Glycerin . . . 5.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass.    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 62.0% by mass

Example 19

—Production of Cyan Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Cyan pigment polymer dispersion in Preparation example 4 . . .        6.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 4.0% by mass (as solid)    -   1,3-butanediol . . . 19.5% by mass    -   Glycerin . . . 6.5% by mass    -   Fluorochemical surfactant having the following Structural        Formula (1) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 61.0% by mass        CF₃CF₂(CF₂CF₂)_(m)—CH₂CH₂O(CH₂CH₂O)_(n)H  Structural Formula (1)

in the Structural Formula (1), ‘m’ is 2, and ‘n’ is 10.

Example 20

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        8.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 6.0% by mass (as solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   Fluorochemical surfactant having the following Structural        Formula (2) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 59.0% by mass

in the Structural Formula (2), ‘Rf’ is CF₂CF₃, ‘m’ is 21, ‘n’ is 4, and‘p’ is 4.

Example 21

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 8 . . .        9.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 2.0% by mass (as solid)    -   1,6-pentanediol . . . 16.0% by mass    -   2-pyrrolidone . . . 2.0% by mass    -   Glycerin . . . 7.0% by mass    -   Fluorochemical surfactant having the following Structural        Formula (3) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 61.0% by mass

in the Structural Formula (3), ‘Rf’ is CF₂CF₃, and ‘q’ is 6.

Comparative Example 1

—Production of Magenta Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Magenta pigment dispersion in Preparation example 3 . . . 6.0%        by mass (as solid)    -   1,6-hexanediol . . . 20.0% by mass    -   Glycerin . . . 5.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2-ethyl-1,3-hexanediol . . . 2.0% by mass    -   Deionized water . . . 60.0% by mass

Comparative Example 2

—Production of Cyan Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Cyan pigment dispersion in Preparation example 4 . . . 6.0% by        mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 4 . . . 3.0% by mass (as solid)    -   1,5-pentanediol . . . 20.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 62.0% by mass

Comparative Example 3

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon Black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   Aquabrid 4720 (manufactured by Daicel Chemical Industries, Ltd.,        acrylic resin: MFT=50° C.) . . . 4.0% by mass (as solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 59.0% by mass

Comparative Example 4

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        10.0% by mass (as solid)    -   PESRESIN A210 (manufactured by Takamatsu Oil & Fat Co., Ltd.,        polyester resin, MFT=20° C. or lower) . . . 4.0% by mass (as        solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   2,2,4-trimethyl-1,3-pentanediol . . . 2.0% by mass    -   Deionized water . . . 59.0% by mass

Comparative Example 5

—Production of Cyan Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Cyan pigment dispersion in Preparation example 4 . . . 6.0% by        mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 3.0% by mass (as solid)    -   1,5-petanediol . . . 20.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   Deionized water . . . 64.0% by mass

Comparative Example 6

—Production of Black Pigment Ink—

Ink composition with the following formula was prepared, and pH wasadjusted to 9 with 10% by mass of lithium hydroxide solution.Subsequently, the ink composition was filtered with a membrane filterwith 0.8 μm of average bore diameter, thereby produced the ink.

<Ink Composition>

-   -   Carbon black pigment dispersion in Preparation example 1 . . .        8.0% by mass (as solid)    -   Silicone modified acrylic resin fine-particles in Synthesis        example 2 . . . 5.0% by mass (as solid)    -   1,3-butanediol . . . 18.0% by mass    -   Glycerin . . . 6.0% by mass    -   Surfactant (Softanol EP7025 manufactured by Nippon Shokubai Co.,        Ltd.) . . . 1.0% by mass    -   3,3-dimethyl-1,2-butanediol . . . 2.0% by mass    -   Deionized water . . . 60.0% by mass

Various evaluations were conducted with respect to the inks of Examples1 to 21 and

Comparative Examples 1 to 6 as follows. The results are shown in Table 1to Table 3.

<Ink Viscosity>

The ink viscosity in each recording ink was measured at 25° C. using anR type viscometer (manufactured by Toki Sangyo Co., Ltd.).

<Content of Silicon (Si) in Recording Ink>

The content of silicon (Si) in each recording ink was measured using ahigh-frequency induction plasma emission spectrometer.

<Volume Average Particle Diameter of Ink>

The volume average particle diameter (D50%) in each recording ink wasmeasured using a particle diameter analyzer (Microtrac UPA manufacturedby NIKKISO Co., Ltd.).

<Visibility of Image>

The ink in Examples 1 to 21 and Comparative examples 1 to 6 was filledin the inkjet printer shown in FIG. 3 to FIG. 5, respectively, andprinting was performed on Type 6200 paper (manufactured by NBS RicohCo., Ltd.) with 600 dpi of resolution. After the printed images dried,two colors were placed one upon another and boundary blotting (bleed)and image blotting (feathering) were visually observed, and theevaluation was conducted according to the following criteria. Further,the image density was measured using a reflective spectrophotometriccolorimetry densitometer (manufacture by X-Rite, K.K.).

[Evaluation Criteria]

A: No blotting occurs, and the image is clear.

B: Hair-like blotting has occurred.

C: Blotting has occurred, so the outline of letters is not clear.

<Fixing Properties>

The ink in Examples 1 to 21 and Comparative examples 1 to 6 was filledin the inkjet printer shown in FIG. 3 to FIG. 5, respectively, andprinting was performed on Type 6200 paper (manufactured by NBS RicohCo., Ltd.) with 600 dpi of resolution. After the printed images dried,the printed portion was rubbed 10 times with cotton cloth, and the stateof transfer of the pigment to the cotton cloth was visually observed andevaluated according to the following criteria:

[Evaluation Criteria]

A: No transfer of the pigment to the cotton cloth was observed.

B: Hardly any transfer of the pigment to the cotton cloth was observed.

C: Slight transfer of the pigment is observed.

D: The pigment is obviously transferred.

<Marker Resistance>

The ink in Examples 1 to 21 and Comparative examples 1 to 6 was filledin the inkjet printer shown in FIG. 3 to FIG. 5, respectively, andprinting was performed to Type 6200 paper (manufactured by NBS RicohCo., Ltd.) with 600 dpi of resolution. After the printed images dried,the printed portion was traced with a fluorescent marker (PROPUS2manufactured by Mitsubishipencil Co., Ltd.), and the state of smearingoccurring due to the removal of the pigment was visually observed andevaluated according to the following criteria:

[Evaluation Criteria]

A: No smear due to discolorment is observed.

B: Hardly any smear due to discolorment is observed.

C: A slight smear is observed.

D: A smear spreads along the marker.

<Ink Discharge Properties>

The ink in Examples 1 to 21 and Comparative examples 1 to 6 was filledin the inkjet printer shown in FIG. 3 to FIG. 5, respectively, andcontinuous printing on 200 sheets was performed to Type 6200 paper(manufactured by NBS Ricoh Co., Ltd.) with 600 dpi of resolution, andthe discharge disorder and the state of no discharge were evaluatedaccording to the following criteria:

[Evaluation Criteria]

A: No discharge disorder or no discharge is observed.

B: Hardly any discharge disorder or hardly any discharge is observed.

C: A discharge disorder and no discharge are observed in 3 nozzles orless.

D: A discharge disorder and no discharge are observed in 4 nozzles ormore.

<Ink Storage Properties>

The ink in Examples 1 to 21 and Comparative examples 1 to 6 was filledin cartridge, respectively, and were stored at 50° C. for 3 weeks.Whether or not the viscosity increase or cohesion occurred was evaluatedaccording to the following criteria.

[Evaluation Criteria]

A: No viscosity increase or cohesion is observed.

B: Hardly any viscosity increase or cohesion is observed.

C: A slight viscosity increase is observed.

D: A viscosity increase and cohesion are remarkable.

<Double Side Printing Properties>

The ink in Examples 1 to 21 and Comparative examples 1 to 6 was filledin the inkjet printer shown in FIG. 3 to FIG. 5, respectively, andprinting was performed to Type 6200 paper (manufactured by NBS RicohCo., Ltd.) with 600 dpi of resolution. Immediately after the printingwas completed on one side, the paper was reversed via an exclusive unit,and printing was performed on another side. This process to 100 sheetswas continuously performed, and sheet smear generating due to rubbingthe ink, which was not penetrated when reversing the sheet, and theconveyance after reversing were evaluated according to the followingcriteria:

[Evaluation Criteria]

A: No ink smear generating due to rubbing upon reversing is observed.

B: The number of sheets where the ink is stuck due to rubbing uponreversing is 10 or less.

C: The number of sheets where the ink is stuck due to rubbing uponreversing is 11 or more.

TABLE 1 Example No. 1 2 3 4 5 6 7 8 9 10 Solid 15 12 10 8 12 10 9 7 2014 content (% by mass) Content of 180 150 98 65 141 90 88 72 390 138silicon (ppm) Viscosity 8.1 8.42 7.65 7.33 8.39 8.6 7.41 8.21 11.76 8.25(mPa · s) Volume 103.5 112.3 146.2 78.6 108.1 116.5 152.9 80.9 118.6110.4 average particle diameter (nm) Image 1.36 1.05 0.95 0.82 1.29 1.070.93 0.84 1.38 1.36 density Feathering A A A A A A A A A A Bleed A A A AA A A A A A Ink B B B B B B B B B A storage properties Ink B B B B B B BB B A Discharge properties Fixing B A B A A A A A A B properties MarkerB A B A A A A A A B resistance Double A A A A A A A A A A side printingproperties

In Example 10, since 1-amino-2,3-propanediol was added, it is confirmedthat the ink storage properties and the ink discharge properties aremore excellent in comparison with other examples.

TABLE 2 Example Comparative example No. 11 12 13 14 15 1 2 3 4 5 Solid 421 10.5 18 18 6 9 12 12 9 content (% by mass) Content of 32 256 18 410185 0 90 0 0 82 silicon (ppm) Viscosity 7.65 9.12 6.55 9.86 9.11 7.217.92 8.06 8.15 7.83 (mPa · s) Volume 85.6 118.9 101.6 105.5 180 143.7113.2 111.4 108 116.8 average particle diameter (nm) Image 0.64 1.4 1.261.26 1.21 0.89 0.98 1.21 1.25 1.01 density Feathering B A B A A B B B BB Bleed B A B A A B B B B B Ink B C B C C B D C C B storage propertiesInk B C B C C B D C C C Discharge properties Fixing C A C B B D C C C Cproperties Marker C A C B B D C D D C resistance Double A A A A A A A AA C side printing properties

TABLE 3 Example Comp. Ex. No. 16 17 18 19 20 21 6 Solid 15 15 10 10 1411 13 content (% by mass) Content of 173 170 51 121 176 62 152 silicon(ppm) Viscosity 15.6 18.0 8.6 8.48 8.53 8.41 7.40 (mPa · s) Volume 98.294.2 121.0 115.1 120.4 112.3 115.6 average particle diameter (nm) Image1.19 1.13 0.90 0.96 1.4 1.38 1.25 density Feathering A A A A A A B BleedA A A A A A B Ink B C B B B B B storage properties Ink C C C B B B BDischarge properties Fixing B C C B B B C properties Marker B C C B B BD resistance Double A A B A A A C side printing properties

In Example 17, since the silicone modified acrylic resin fine-particlesnot containing the reactive silyl group with 10 nm of average particlediameter in Synthesis example 7 was added, a large amount of surfactantis required upon synthesis, so a large amount of surfactant will becontained in the formed ink coating. As a result, sufficient filmstrength cannot be obtained, and the fixing properties and markerresistance becomes inferior in comparison to those of other examples.

INDUSTRIAL APPLICABILITY

The recording ink of the present invention is with excellent dischargestability and storage stability, rapidly penetrates into a recordingmedium and forms a coating, and will never generate smearing uponhigh-speed printing or double-sided printing, and excels in markerresistance, and enables high quality image recording with less bleeding,and is preferably used for an ink cartridge, ink record, and an inkjetrecording apparatus, and an inkjet recording method.

The inkjet recording apparatus and inkjet recording method of thepresent invention are applicable to various recording in an inkjetrecording system. For example, the inkjet recording apparatus and inkjetrecording method of the present invention can be particularly preferablyapplied to inkjet recording printers, facsimiles, copy machines, andprinter/fax/copy complex machines.

1. An inkjet recording method comprising: discharging recording inkdrops to form an image by applying an impulse to a recording ink,wherein the recording ink comprises at least water, a colorant, a resinfine-particle, a water-soluble organic solvent, and a penetrant, whereinthe penetrant is a diol compound having 7 to 11 carbon atoms and theresin fine-particle is a silicone modified acrylic resin not containinga hydrolyzable silyl group and wherein the silicone modified acrylicresin not containing a hydrolyzable silyl group is obtained bypolymerizing at least one acrylic monomer with at least one silanecomprising at least one hydrolyzable group, and wherein no hydrolyzablesilyl group remains as a result of said polymerizing.
 2. The inkjetrecording method according to claim 1, wherein the impulse is at leastone selected from heat, pressure, vibration, and light.
 3. The inkjetrecording method according to claim 1, wherein a volume average particlediameter of the resin fine-particle is 10 nm to 300 nm.
 4. The inkjetrecording method according to claim 1, wherein the silicon quantityoriginated from the silicone modified acrylic resin in the recording inkis 50 ppm to 400 ppm.
 5. The inkjet recording method according to claim1, wherein the minimum film forming temperature (MFT) of the resinfine-particle is 20° C. or lower.
 6. The inkjet recording methodaccording to claim 1, wherein the water-soluble organic solvent is atleast one selected from glycerin, ethylene glycol, diethylene glycol,triethylene glycol, propylene glycol, dipropylene glycol, tripropyleneglycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol,3-methyl-1,3-butanediol, 1,5-pentanediol, tetraethylene glycol,1,6-hexanediol, 2-methyl-2,4-pentanediol, polyethylene glycol,1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone,N-methyl-2-pyrrolidone and N-hydroxyethyl-2-pyrrolidone.
 7. The inkjetrecording method according to claim 1, wherein the colorant is at leastone of a pigment, a dye and a colored fine-particle.
 8. The inkjetrecording method according to claim 7, wherein the colorant is at leastone pigment, and the pigment comprises at least one hydrophilic group onthe surface, and is at least one of water dispersible and water solublein the absence of a dispersant.
 9. The inkjet recording method accordingto claim 7, wherein 0.05 parts by mass to 1.2 parts by mass of thesilicone modified acrylic resin fine-particles not containing ahydrolyzable silyl group is added relative to 1 part by mass of thepigment.
 10. The inkjet recording method according to claim 1, whereinthe recording ink further comprises a nonionic surfactant wherein thenonionic surfactant is at least one selected from an acetylene glycolsurfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenylether, polyoxyethylene alky ester and polyoxyethylene sorbitan fattyacid ester.
 11. The inkjet recording method according to claim 1,wherein the recording ink further comprises a fluorochemical surfactant,wherein the fluorochemical surfactant is at least one selected from thefollowing Structural Formulae (1), (2) and (3),CF₃CF₂(CF₂CF₂)_(m)—CH₂CH₂O(CH₂CH₂O)_(n)H  Structural Formula (1) in theStructural Formula (1), ‘m’ is an integer of 0 to 10, and ‘n’ is aninteger of 1 to 40,

in the Structural Formula (2), ‘RF’ is CF₃ or CF₂CF₃, ‘m’ is an integerof 6 to 25, ‘n’ is an integer of 1 to 4, and ‘p’ is an integer of 1 to4,

in the Structural Formula (3), ‘RF’ is CF₃ or CF₂CF₃, and ‘q’ is aninteger of 1 to
 6. 12. The inkjet recording method according to claim 1,wherein the recording ink further comprises an anionic surfactant,wherein the anionic surfactant is at least one selected frompolyoxyethylene alkyl ether acetate and dialkyl sulfosuccinate salt. 13.The inkjet recording method according to claim 1, wherein the recordingink further comprises an aminopropane diol compound.